The TARDIS materialises near a lighthouse on an island in the English
Channel, where a boat carrying several high-society passengers has just
capsized. The lighthouse itself has suffered mysterious energy drains
and the death of one of its technicians. The Doctor and Leela discover
that a shapeshifting Rutan has infiltrated the island and is about to
summon its mothership to Earth. As the lighthouse's occupants are killed
off one by one it appears that, this time, the Doctor may be too late to
save anyone.

Production

One of the first writers approached by Robert Holmes to contribute to
Doctor Who's fifteenth season was Terrance Dicks, Holmes'
predecessor as the programme's script editor. Dicks' last Doctor
Who adventure had been Season Thirteen's The
Brain Of Morbius, which had experienced some growing pains to
bring it in line with Holmes and former producer Philip Hinchcliffe's
more gothic vision of the series. In the hope of conceiving a story idea
that would be more to Holmes' liking, Dicks drew on some elements of a
rejected vampire serial called “The Haunting” he had
submitted in 1974. The result was a new storyline entitled “The
Witch Lords”, which was in development by the end of November
1976.

Dicks' adventure was commissioned under the title “The Vampire
Mutation” on January 11th, 1977. Although it was favoured to be
the first story of Doctor Who's fifteenth season, it was intended
to be made second after The Invisible
Enemy, and so was designated Serial 4U. When script delays arose
on The Invisible Enemy in late January, the
production slate was brought into line with the planned transmission
schedule, with “The Vampire Mutation” now leading off
Doctor Who's fifteenth recording block.

The Vampire Mutations was
abandoned for fear that it would be seen as a parody of the BBC's
forthcoming Dracula adaptation

In February, however, calamity struck: Holmes and producer Graham
Williams were informed by Head of Drama Graeme McDonald that “The
Vampire Mutation” should be abandoned, due to fears that it would
be viewed as a parody of the BBC's prestigious forthcoming adaptation of
Bram Stoker's novel Dracula. With no replacement script
immediately available, this forced The Invisible
Enemy back into the first slot of the recording schedule.

Nonetheless, Holmes was still eager to involve Dicks in Season Fifteen,
and the writer was agreeable to supplying a new script at very short
notice. Holmes suggested a story involving a small number of characters
and sets based around a lighthouse, offering Wilfrid Gibson's 1912 poem
Flannan Isle as suitable inspiration. The poem itself was based
upon true events which occurred in 1900, when a supply ship discovered
that the lighthouse crew on the Flannan Isles in the Outer Hebrides had
vanished without a trace. Dicks also recalled Ray Bradbury's 1951 short
story The Fog Horn, about an aquatic dinosaur which has survived
in the ocean's depths but is attracted by the call of a lighthouse's fog
horn.

By early March, Dicks had prepared a treatment entitled “Rocks Of
Doom”, which he quickly began turning into full scripts (these
were retroactively commissioned on March 29th). Several character names
were changed in the process: Joshua Crockett became Reuben, Davy
Williams became Vince, Lord Peach-Palmer became Lord Palmerdale, and
Herbert Burkin became Harker. Skinsale's first name changed from John to
Jimmy, while Adelaide's surname went from Couchon to Lessage. One
character -- Skinsale's wife, Veronica -- was deleted entirely.

Holmes suggested that the monster in the story should be a Rutan; these
aliens had previously been described as the Sontarans' eternal foe in
Holmes' own The Time Warrior (which had
been script edited by Dicks). Holmes also asked Dicks to include the
sequence in which Leela's eyes change from blue to brown. Williams had
promised this development to Louise Jameson when she signed her contract
for Season Fifteen, because she found her coloured contact lenses to be
very uncomfortable.

Dicks worked quickly, completing his scripts by the end of March. In
the interim, new titles such as “The Monster Of Fang Rock”
and “The Beast Of Fang Rock” were apparently considered,
before Horror Of Fang Rock was finally selected. This was now
referred to as Serial 4V (since the “4U” code had been
dropped to avoid confusion in production paperwork).

There was no space available at BBC TV Centre, so Horror Of Fang Rock would be made at Pebble Mill
in Birmingham

Having originally been contracted for “The Vampire
Mutation”, the director assigned to Horror Of Fang Rock was
Paddy Russell, returning to Doctor Who after a two-year absence
since Pyramids Of Mars. Unfortunately,
Russell felt that Horror Of Fang Rock was a much poorer story
than Dicks' original effort, and was particularly underwhelmed by the
lighthouse locale. Not only would this mean dealing with a lot of curved
sets (which made filming laborious), but the exterior walls of the lamp
room -- in which much of the action took place -- would have to be
largely glass and hence transparent, with a background achieved via
Colour Separation Overlay, limiting Russell even further.

Meanwhile, yet another problem arose when it was discovered that there
was no space available at BBC Television Centre to record Horror Of
Fang Rock. Ultimately, it was decided to record the serial at Pebble
Mill in Birmingham, marking the first time in Doctor Who history
that studio taping had taken place outside London. However, this move
aroused concern in several members of the crew: Doctor Who would
be by far the most ambitious drama production ever staged at Pebble
Mill, and would even require the installation of new equipment.

First, though, model filming took place on the Visual Effects
Department Model Stage in London between April 26th and May 2nd,
followed by filming of the scenes on the rocks at the Ealing Television
Film Studios from May 4th to 6th. Rehearsals for Horror Of Fang
Rock marked a turning point in the relationship between Tom Baker
and Louise Jameson. To date, Baker had been quite dismissive of his
costar, both because he felt that Leela's violent tendencies were
inappropriate for Doctor Who, and because he did not want to be
saddled with a companion of any sort. By now, Jameson had been on
Doctor Who long enough that she began to stand up for herself and
her character, and this led to Baker finally apologising for his
attitude towards her.

Also in a state of evolution at this point was the Doctor Who
production team. Holmes had originally considered departing at the end
of Season Fourteen, but Williams had persuaded him to stay on for six
extra months. By the end of April, Holmes had confirmed to Williams that
he still intended to leave as scheduled. As his replacement, Holmes
first suggested his own predecessor: Dicks himself, who was not
interested in returning to the Doctor Who production office
full-time.

The Pebble Mill staff were keen to attract productions
away from London, and made an exceptional effort to be helpful

Holmes then recommended Anthony Read, a longtime acquaintance of both
himself and Williams who had recently approached the Doctor Who
production office about contributing to the series. Read was a former
producer and script editor on programmes such as The
Troubleshooters, and had also written for Sutherland's Law
and Z Cars. Graeme McDonald was interested in bringing Read back
into the BBC fold, and script editing Doctor Who proved to be
just the lure McDonald needed. In early May, Read agreed to handle the
final serials of the current season, as well as the entirety of Season
Sixteen.

Meanwhile, good news finally greeted Horror Of Fang Rock as cast
and crew arrived in Birmingham. Despite the misgivings about Pebble
Mill's ability to handle Doctor Who, Russell and her team quickly
discovered that the studio's lack of pedigree was a blessing in
disguise. The Pebble Mill staff were keen to attract even more
productions away from London, and consequently made an exceptional
effort to be as helpful and efficient as possible -- even stealing
cameras from an adjacent studio to ensure that one sequence was recorded
the way Russell wanted.

The first studio block took place on May 25th and 26th, covering
episodes one and two, respectively. This was followed by a three-day
session from June 7th to 9th. The first day dealt with part three, while
the final installment was recorded across the remainder of the block.
June 9th was also used for various special effects sequences, as well as
the point-of-view shots of the lamp room in part two. Unfortunately, the
inadequacies of Pebble Mill became particularly obvious during the final
day of recording. Colour Separation Overlay had only rarely been used at
Pebble Mill in the past but was employed liberally throughout Horror
Of Fang Rock. Consequently, there were numerous delays in completing
these shots, causing many tempers to fray on set.

In addition to all of the technical and logistical difficulties on
Horror Of Fang Rock, Russell had also developed a tense
relationship with Baker and Jameson, who found the director too
uncompromising. Exhausted and frustrated after the serial's completion,
Russell vowed never to work on Doctor Who again; the debut
installment of her final Doctor Who serial rang in Season Fifteen
on September 3rd. Russell went on to helm episodes of The Omega
Factor (with Jameson), Emmerdale Farm and other programmes
before retiring from television in the early Eighties.